1. Field of the Invention
The invention relates to an opening roller for a spinning mill machine for the opening and cleaning of cotton fibers. It is concerned particularly with an opening roller provided with a predetermined number of beater elements distributed on and fixed to the periphery of the opening roller for grasping and opening flocks of cotton fibers.
2. Description of Related Art
Opening rollers for so-called coarse cleaning machines are well known. For example, Maschinenfabrik Rieter AG markets such a machine under the brand name Mono Roller Cleaner B4/1. The same company has applied for letters patent in Switzerland for a further machine of this type under the number CH-00321/89-0.
These machines have beater elements distributed on the periphery of the opening roller. Such beater elements are round rods fastened radially to the periphery. They are distributed in a predetermined manner over the peripheral surface.
In these machines the fibrous material is fed toward the periphery of the roller at one axial end thereof and collected there by the beater elements. The beater elements pull the material (usually in the form of flocks over cleaning grid bars. Gradually the material is brought to the other axial end of the opening roller by means of guide chambers, where the opened fibers are conveyed through the outlet of the machine by means of centrifugal force.
The cleaning machine disclosed in Switzerland Patent Application No. CH-00321/89-0 is represented semischematically in FIGS. 1 and 2, to facilitate explanation later on of the principles of the present invention on the basis of this representation.
3. SUMMARY OF THE INVENTION
It is desirable that the opening effect of such machines be more efficient, that is to say, that the flocks be fed more efficiently with the power input remaining the same or smaller, and/or with the fiber flocks fed in being opened more efficiently and if possible, more gently. Hence, the term "more efficiently," means an increase in the opening of large fibers flocks into a plurality of smaller flocks. As far as possible according to the principle of cotton cleaning, the cleaning means primarily opens the flocks, in order to be able to remove the dirt adhering to and between the fibers more effectively.
According to the present invention, the beater elements no longer have simple surfaces directed radially to the axis of rotation of the opening roller. Rather, the beater elements according to the invention have fiber-contacting rod portions that are inclined forwardly in the direction of rotation of the opening roller surface on which they are received.
An advantage of the beater elements according to the invention lies in that the fiber flocks are thrown about less by impacts with the beater elements. Rather, they are grasped by means of the beater elements in a small part of the fiber bunch and the fiber bunch is subsequently pulled through the surrounding air as a tuft which is opened into smaller parts through the retarding tendency of the surrounding air.
For good cleaning in a machine of this type, it is desirable that the fiber bunch remain as long as possible on the beater elements and be pulled by the beater elements over the cleaning grid. That is to say, the relative speed between the fiber bunch and the beater elements should be as small as possible while the fiber bunch is being pulled over the cleaning grid.
The desired action might be likened to a kind of pinching of the fiber bunches in a way that only a small part of each fiber bunch is actually engaged by the pinching components, leaving the biggest part of the fiber bunch free to be beaten intensively by means of the grids without producing a rolling effect between the beater element and the grid bars. Rolling of the fiber bunches is disadvantageous, because rolling effects are accompanied by a danger of producing entanglement of fibers which may lead later on at least to a certain amount of neps.
The present invention provides a beater rod arrangement that functions in a manner comparable in some respects to a fiber pinching system. The fiber bunch contacting portions of the beater rods are not too thick and are arranged in a way that the bunch is kept by the rod portions over the grid bars for as long a distance as possible.
Also, the fiber bunch should come back to the beater elements after the cleaning grid, in order to be transported properly through the cleaning machine. The fiber flocks move a stage further in the axial direction of the opening roller in a transfer chamber to be described later. Subsequently they are grasped again by further beater elements, and so on stage by stage, until the fiber bunch, reduced in size and cleaned, leaves the machine on the other axial end of the opening roller.